Re: [PATCH] x86/efi: Restore Firmware IDT in before ExitBootServices()

From: 'Joerg Roedel'
Date: Fri Aug 20 2021 - 04:52:35 EST


On Fri, Aug 20, 2021 at 08:43:47AM +0000, David Laight wrote:
> Hmmm...
> If Linux needs its own IDT then temporarily substituting the old IDT
> prior to a UEFI call will cause 'grief' if a 'Linux' interrupt
> happens during the UEFI call.

This is neede only during very early boot before Linux called
ExitBootServices(). Nothing that causes IRQs is set up by Linux yet. Of
course the Firmware could have set something up, but Linux runs with
IRQs disabled when on its own IDT at that stage.

Regards,

Joerg